1. Field of the Invention
The invention relates to an optical touch module, and more particularly to an optical touch module utilizing an image capture unit to determine touch signals.
2. Description of the Related Art
Conventional touch modules are usually resistance type touch modules due to cost considerations. Meanwhile, other developed touch module technologies include infrared, ultrasonic and surface capacitive type technologies. Currently, large sized touch panels are popular. Of the new technologies, optical touch modules utilizing image capture units for multiple touch points have been disclosed.
FIG. 1 is a schematic view of a conventional optical touch module. Referring to FIG. 1, the conventional optical touch module 10 comprises a touch panel 11, two image capture units 12 and 13, three reflective elements 14, 16 and 17 and a frame 15. The image capture units 12 and 13 are respectively disposed on the right corner and the left corner of the touch panel 11. Light sources 18 and 19 are respectively disposed adjacent to the image capture units 12 and 13. For example, the light sources 18 and 19 emit infrared rays, and the infrared rays are reflected along an initial path via the reflective elements 14, 16 and 17. The image capture units 12 and 13 capture the reflected light to determine touch signals.
However, the above optical touch module 10 has disadvantages. First, because the reflective elements 14, 16 and 17, and the image capture units 12 and 13 are directly disposed or fixed on the touch panel 11, the touch panel 11 is easily damaged and broken while re-working and repairing.
Additionally, referring to FIG. 1, as shown, light from the left light source 18 directly enters the right image capture unit 13 shown as arrow A1. Similarly, light from the right light source 19 directly enters the left image capture unit 12 shown as arrow A2. Thus, because light of the light sources directly enter the opposite image capture units, sensors (not shown) thereof may result in blooming phenomenon, wherein signals thereof are wrongly determined and noise is generated.
Moreover, if light from the light source 19 at the top right corner is partially reflected to the image capture unit 12 at the top left corner (shown as arrow B), signals thereof may be wrongly determined and noise may be generated. Similarly, if light from the light source 18 at the top left corner is partially reflected to the image capture unit 13 at the top right corner via the reflective element 14 adhered to the lower side, signals thereof may be wrongly determined and noise may be generated.
In summary, the structure of the optical touch module 10 may make the touch panel 11 broken while re-working and repairing, and make signals being wrongly determined due to the reflected light.